Després de dinar, la mare es renta les mans al bany.

Because després de + infinitive is a very common Catalan pattern meaning after doing something.

So:

• després de dinar = after having lunch
• després de sopar = after having dinner
• després de treballar = after working

Even if English might translate this naturally as after lunch, Catalan is often using the infinitive structure.

Grammatically, learners usually treat it here as an infinitive verb: to have lunch.

So després de dinar literally works like after having lunch.

That said, in English the most natural translation may simply be after lunch. Catalan often uses meal words this way, so the line between noun-like and verb-like meaning can feel blurry to an English speaker.

Catalan often uses the definite article with family members:

• la mare = mother / mom
• el pare = father / dad

This is very normal when you are talking about the person, not directly addressing them.

A few useful contrasts:

• La mare arriba tard. = Mom is arriving late.
• Mare, vine! = Mom, come here!
  
  • In direct address, the article is normally dropped.
• la meva mare = my mother
  
  • This is also correct, but it sounds more explicit. If the context already makes it clear whose mother you mean, Catalan often prefers just la mare.

Because Després de dinar is an introductory time phrase placed at the beginning of the sentence.

The comma helps separate that opening element from the main clause:

• Després de dinar, la mare es renta les mans al bany.

This is similar to English punctuation in sentences like:

• After lunch, Mom washes her hands in the bathroom.

Because the verb here is being used reflexively: the mother is washing herself.

The basic verb is rentar = to wash.
The reflexive form is rentar-se = to wash oneself.

So:

• renta = washes
• es renta = washes herself

In this sentence, es goes before the conjugated verb:

• la mare es renta

That is the normal position for this kind of pronoun with a finite verb.

Because Catalan usually uses the definite article with body parts when the owner is already clear.

So Catalan prefers:

• es renta les mans = washes her hands

rather than:

• es renta les seves mans

This is very common with body parts and clothing:

• Em rento la cara. = I wash my face.
• Es posa la jaqueta. = He/She puts on his/her jacket.

Using les seves mans is possible, but it usually sounds more emphatic, contrastive, or less natural in an everyday sentence.

In a sentence like this, es marks the person affected by the action, while les mans is the thing being washed.

So the structure is roughly:

• la mare = subject
• es = reflexive pronoun
• renta = verb
• les mans = direct object

A useful way to think about it is:

• She washes herself on the hands -> natural English: She washes her hands

You do not need to translate it word for word, but this helps explain why Catalan uses both es and les mans.

Al is the contraction of a + el.

So:

• a + el bany -> al bany

And bany is masculine singular, so the contraction happens automatically.

In this sentence:

• al bany = in the bathroom / to the bathroom, depending on context

Here it clearly means location: in the bathroom.

Because Catalan often uses a where English uses in or at for location.

So al bany is a normal way to say:

• in the bathroom
• at the bathroom, depending on context

This is one of those places where you should avoid translating prepositions too literally. English and Catalan do not divide up in / at / to in exactly the same way.

Yes. The sentence is natural as written, but Catalan allows some flexibility.

For example, you could also say:

• La mare es renta les mans al bany després de dinar.

That puts the time phrase at the end instead of the beginning.

The original version:

• Després de dinar, la mare es renta les mans al bany.

puts the time setting first, which is very common and natural.

Renta is the present indicative, third person singular, from rentar.

So:

• jo rento = I wash
• tu rentes = you wash
• ell/ella renta = he/she washes

In this sentence, the present tense can describe:

• a habitual action
• a general routine
• a simple example sentence

So it works much like the English present in Mom washes her hands after lunch.

Yes, but the meaning shifts a little.

• després de dinar = after having lunch / after lunch
• després de menjar = after eating
  
  • more general; not specifically lunch
• després del dinar = after the lunch / after the meal
  
  • more noun-like, often referring to a specific lunch or the lunch meal as an event

So for the sentence you were given, després de dinar is the most natural choice if the idea is specifically after lunch.